The directorial swansong of Steven Soderbergh, Behind the Candelabra is a biopic of the showman and pianist Liberace, once the highest paid musician in the world. After a lifetime spent denying his homosexuality and suing those who wrote about it, Liberace died of Aids in 1987 – and his secret was out.

The film begins in 1977 with a sonic blast from Donna Summer, as we meet the young Scott Thorson (Soderbergh regular Matt Damon), who’s working as an animal handler on a commercials set when a chance hook-up in a gay bar with a rather swish Scott Bakula leads him backstage at a Liberace show in Vegas. The musician is played, on effete hiatus, by Michael Douglas. Before you know it, Thorson is installed in the über-bling Liberace house, kitted out in a chauffeur’s uniform and driving the Rolls-Royce on stage at the Vegas shows.

Liberace’s Polish mother Frances, incarnated by Debbie Reynolds, is never far away, hovering like an unspoken reproach. The relationship between Thorson and Liberace, played out in plain sight yet also completely secret, lasts five years. But inevitably, as Thorson ages, Liberace’s eye wanders – he has an insatiable appetite for young men. Wounded, Thorson succumbs to cocaine addiction and an amphetamine-induced slimming programme known with sly precision as the ‘California Diet’. He’s kicked out, sues, settles, and goes to work for the postal service in West Hollywood.

The title Behind the Candelabra comes from Thorson’s own account of those years together. The image of a candelabra carefully placed on a grand piano was a key piece of branding for Liberace – he even incorporated it into his written signature – and the movie is careful to mention its origins: it’s taken from a Chopin biopic made by Charles Vidor in 1944, in which the composer has a candelabra on his piano. For Liberace it suggested Poland, style and a bit of class, and perhaps even a touch of tubercular tragedy. (Chopin’s music is played in the movie.)

Thorson exchanged the gold-plated Rolls-Royce Liberace gave him for a mountain of cocaine, but the film leaves out some of the wilder parts of his book – including his witnessing the events leading up to the Laurel Canyon gangland murders of 1981, which were depicted in the 2003 Val Kilmer film Wonderland (Thorson gave evidence at the subsequent trial of Eddie Nash). Thorson has consistently denied that he’s gay, which doesn’t quite square with the thesis of this movie.

Both Damon and Soderbergh have said that they want this to be a love story, but in truth it’s hard to see the love. This Liberace displays thick layers of sugared neediness that wouldn’t disgrace a Polish murzynek cake, though there are moments of genuine tenderness in the bedroom scenes, and we understand that Liberace is genuinely touched by Scott’s sad backstory – he was an orphaned foster-child. But there’s also the chilling response to his mother’s death: “I’m free!” This isn’t the “winking… heap of mother love” of the famous Daily Mirror libel of 1956, when Liberace successfully sued the newspaper for implying that he was gay.

Douglas brings a preening, nervous energy to a performance that may well prove to be the best of his career; his real-life health problems give a genuine air of mortality to his physical presence, the furs and glittering clothes hanging on him like a snake about to shed its skin. If there is one criticism it’s that he never quite shows the charm of the man, the softness of his face and manner, which you can see in any YouTube video. Nor does the film ever elaborate on his legendary rapport with his audience, whom he would invite on stage at the end of his shows. (He appears, too, to have been rather more generous to Thorson than is shown in the film.) The Soderbergh Liberace is necessarily, for the purposes of the drama in hand, more isolated and more distant than he was in real life.

Damon, meanwhile, plays his Thorson slightly numb and along for the ride, and seems entirely passive, except in the sack. The craziness is, one suspects, very toned down from what really went on. There’s an exemplary supporting cast, with Dan Aykroyd almost unrecognisable as Liberace’s manager Seymour Heller; cast completely against type, he’s especially good in a villainous role.

Soderbergh’s Liberace avoids the dilemmas of his life by hard work, and the director cleverly creates an early scene which shows off the skill of the man, spotlight on hands as he whirrs through a boogie-woogie number. The recording is of Liberace himself, but we have no doubt that Douglas is playing it. The scenes at home, often in a hot-tub or watching old videos of himself, induce a sense of perfumed claustrophobia.

This is a well-made film, produced for HBO after Soderbergh failed to secure mainstream funding on the grounds that the subject-matter was ‘too gay’. It’s in the tradition of the director’s more sexually charged films, such as Full Frontal (2002) or even sex, lies, and videotape (1989), whose title perfectly sums up Liberace’s downtime at home. The first part of the film is played, sometimes rather uncomfortably, for laughs, inducing a queasy sense of sniggering at the silly fags. Technically it’s immaculate, moving easily between broad strokes and small ones – suggesting Learjet travel via a few blurred images, for example, or hiding Damon’s age in the early scenes (he’s 41 playing 16) with an effect somewhat akin to – there’s no other way of saying this – Vaseline on the lens.

It’s highly tempting to project Soderbergh’s own public disillusionment with Hollywood on to this story about a gilded cage and the corrupting power of showbiz and money. There is a kind of funereal grandeur at work here, a powerful voodoo sense of summoning ghosts, confirmed by the revelation in the press notes that both Reynolds and Douglas knew Liberace (Reynolds was part of an inner circle) and that the boogie-woogie scene involved his two pianos reunited, for the first time since his death, on the Vegas stage where he played them; the LA apartment too was Liberace’s own, and the post-office desk in West Hollywood is also the actual place where Thorson worked after the party was over.

The script is by Richard LaGravenese (The Fisher King, The Bridges of Madison County), who brings economy to a gloriously bedizened subject-matter. Particular mention must go to costume designer Ellen Mirojnick, whose task was at once easy and difficult. A long-time collaborator of Douglas’s, Mirojnick had special access to the original costumes and jewels at the Liberace Museum, but had to recreate them in much lighter materials. (For one of his entrances, Liberace wore a $300,000 white fox coat lined in $100,000 worth of sequins and crystals, with a 16-foot train; it weighed a hundred pounds.)

Reviewers often search for amusing juxtapositions to explain a movie’s essence, and for Behind the Candelabra it would probably be Mommie Dearest meets Salò. Soderbergh ends the movie with exemplary grace, solving the puzzle of how to avoid a downbeat conclusion with a solution that would have made Derek Jarman proud – the funeral in Palm Springs (partly filmed at the actual church) becomes an exhilarating ascension into gay heaven, with the ceremony turning into a fantastical extravaganza in the mind of Thorson – who is rendered alone in the church as the show unfurls.